Missing Ridge on Trusses

[Kenny Rigler]

Hey Guys-

There was no ridge board in between the trusses on this 20+ year-old ranch style home. Is it possible these were designed to not need one? About every other truss had a 2x2 than connected the two trusses. Thanks.

Kenny

[Joe Funderburk, CMI]

There's never a ridge board with trusses, but they usually are one piece across the roof. This looks like a modular home to me.

[Jeffrey R. Jonas]

Looks like a modular to me also.

[Greg Bell]

Thats what I thought when I looked at the photos.

[Kenny Rigler]

It didn't have the typical construction that I usually see with the modulars, other than the trusses. I didn't see any problems associated with the lack of the ridge but wanted to double-check.

[Jeffrey R. Jonas]

Originally Posted by krigler

It didn't have the typical construction that I usually see with the modulars, other than the trusses. I didn't see any problems associated with the lack of the ridge but wanted to double-check.

Was the home in an area where it would have been difficult to get a truck with full-size trusses to the site? Could be custom for a particular situation. I built a home back in the 90's with no access for large/long trucks for the last 250 ft. We had to carry the trusses in by hand. Design did not allow for split trusses.

[Nick Gromicko]

From a purely structural standpoint, you don't really need a ridge board on a stick-built roof either. It just makes it easier to frame with one.

[Jeffrey R. Jonas]

Originally Posted by gromicko

From a purely structural standpoint, you don't really need a ridge board on a stick-built roof either. It just makes it easier to frame with one.

True, but rafters actually connect together, where-as the trusses in the OP's pic's do not.

[Kenny Rigler]

Originally Posted by jjonas

Was the home in an area where it would have been difficult to get a truck with full-size trusses to the site? Could be custom for a particular situation. I built a home back in the 90's with no access for large/long trucks for the last 250 ft. We had to carry the trusses in by hand. Design did not allow for split trusses.

No, it was in a pretty typical open residential area. Here are a few more exterior pics and a shot of the floor structure.

Kenny

[Joe Funderburk, CMI]

Anyone see any lateral or diagonal bracing?

[mnahrgang]

I would think the only way these would work would be if you had a structural wall/support under the center of these to hold them up. The reason regular trusses work is because all the downward pressure of the roof, is directed into the exterior walls and then down to the foundation. With no support under these, they would ultimately collapse from the downward pressure. If it's a 20+ year old house, and that hasn't happened then I'm wondering why. I mean, you don't need a ridge, but they do need to touch for the geometry to work.

[Jeffrey R. Jonas]

In the pic's... I assume the pier is in the centerline of the home. Did the beam look to be a double, butted up and fastened together? In-line with the ridge? A load bearing wall in between? (Kinda like a manufactured home)?
Even the Rake boards would indicate this.
Still resembles a modular home to me.

[Kenton H. Shepard, CMI]

On many truss sets, they don't even require ridge blocking between trusses. I've never seen a ridge installed with trusses. Ridges mainly serve to make it easier to stand rafters, and in seismic areas they provide boundry nailing to improve the strength of the roof membrane.

Ridge blocks generally make it easier stand trusses more quickly, which is an advantage when the carpenters are doing piece work (getting paid by what they get done instead of by the hour) which is typical in production work.

[Paul Pendley]

Nicely done crawl space by the way.

[John Allingham]

I don't get it either. What's stopping that whole roof structure from sagging in the middle and closing up those gaps?